An adhesive preparation to be attached to skin includes a pressure-sensitive adhesive layer formed on one side or both sides of a backing thereof and is intended to administer a drug from the skin to the body via the pressure-sensitive adhesive layer to prevent or treat a disease locally or in a whole body.
Such an adhesive preparation is required to have sufficient adhesiveness on attaching to a skin, and is required to be able to be peeled and removed from the skin without causing contamination of the surface of skin after use (for example, occurrence of adhesive deposit, stickiness or the like). In addition, the adhesive preparation is desirably low in irritation to the skin.
PTL 1 discloses an adhesive preparation that uses an acrylic pressure-sensitive adhesive obtained through polymerization of an alkyl (meth)acrylate and a monomer copolymerizable with the alkyl (meth)acrylate and containing neither a carboxyl group nor a sulfo group. Further, in the adhesive preparation in the literature, the pressure-sensitive adhesive layer contains an organic liquid component and is crosslinkable. The adhesive preparation is said to have a sufficient cohesive power so as not to cause adhesive deposit in peeling, be low in irritation to the skin and have a soft feeling. However, the pressure-sensitive adhesive having neither a carboxyl group nor a sulfo group disclosed in PTL 1 possibly peels off from the skin when it is attached to a skin surface for a long period of time or when it is attached to a largely moving skin surface, and further improvement of adhesive properties is required.
PTL 2 discloses an adhesive preparation that contains, in the pressure-sensitive adhesive layer thereof, a crosslinked product of a copolymer formed of an alkyl (meth)acrylate or a mixture of the ester and an alkoxyalkyl (meth)acrylate, and a monomer containing a carboxyl group and/or a hydroxyl group. However, when the pressure-sensitive adhesive layer in the adhesive preparation contains a carboxyl group-containing copolymer and bisoprolol as a drug, there is a concern that the carboxyl group is subjected to the action of bisoprolol to disturb release of the drug from the adhesive preparation, thereby lowering the utilization rate of the drug.
On the other hand, when a hydroxyl group-containing copolymer is contained, good adhesiveness to skin is exhibited and there would be no concern that the release of the bisoprolol from the adhesive preparation is disturbed. However, the hydroxyl group may be subjected to the action of bisoprolol to cause deviation of pressure-sensitive adhesive properties, for example, increase in holding power thereof during preservation, etc.